Among the many candidates for genome sequencing, what makes Neurospora stand out? Most importantly for comparative biology, Neurospora species are characterized by genetic and reproductive isolation, and phylogenetic relationships among the species are well supported with carefully estimated divergence times. It is clear from studies of yeast, worms, and primates that comparative genomics is most effective when one has access to several genomes with a range of divergence times. With the addition of the two Neurospora species to be sequenced in this project, N. discreta and N. tetrasperma, it will be possible to make comparisons across a span from 80 million years ago (MYA) to 3 MYA. The possible comparisons parallel those between primate and rodent, Caenorhabditis elegans and C. briggsae (75-100 MYA), mouse and rat, (25-33 MYA), yeast species (10-30 MYA), or chimp and human (5 MYA). The Neurospora comparisons (3 MYA) extend further through time than existing systems, which will permit comparison of more rapidly evolving regions. The completion of this project will create an environment for genomic comparative biology that will be unsurpassed for studies of genome evolution.
The physical attributes and growth habit of Neurospora make it favorable for population genetics and ecology. Individuals are macroscopic and easily found in nature. They grow rapidly, and they are large enough to provide protein or RNA for proteomics or transcription profiling, which would be extremely difficult with microscopic, single-celled microbes such as yeasts or bacteria. Neurospora is a member of the Pezizomycotina, home to the largest group of plant pathogenic fungi. To take one example, plant pathogens make many polyketides, and some of them are virulence factors; N. crassa has seven polyketide synthase genes, whereas yeasts have none. As a model for genome evolution in pathogenic fungi, Neurospora is a much better model than yeast. Neurospora also has been the subject of research on lignin biodegradation and, given the range of genetics possible with Neurospora, it is an excellent system in which to study the genetics of the regulation of lignin biodegradation.
Principal Investigators: John W. Taylor and N. Louise Glass (Univ. of California, Berkeley), David J. Jacobson (Stanford Univ.), and Donald O. Natvig (Univ. of New Mexico).